Azo-dyestuffs and process of making same



Patented Apr. 25, 1933 I UNITED TAT S PATENTQOFFICE EEIEDEIGH rELrx ANDWILHELM HUBER, F BASE-L, SWITZERLAND, Assrenons r0 SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF-BASEL, SWITZERLAND AZO-DYESTUFFS AND PBOGES OF MAKING SAME No Drawing. Application filed November 30, 1932, Serial No. 645,134, and in Switzerland December'2 1, 1 931,

The present invention relates to the manufacture of new azo-dyestufis. .It comprises the process of making these azo-dyestufis, and the azo-dyestutfs themselves.

According to this invention esters and others of cellulose, particularly acetate silk,

are dyed fast tints by dyestuffs made by causing an aromatic diazo-compound of'the benzene series, which contains no substituents capable of bringing about solubility in dilute aqueous caustic alkalies, such as for example the sulfonic acid, hydroxyl-, carboxyl-, sulfamide-group, etc., to act on 1- amino-3-hydroxybenzene in such media the pH of which is not greater than 7 so that the coupling occurs in ls-position, and subsequently acylating the dyestufi thus produced with acylating agents which introduce the residue of an aliphathic carboxlyic acid of low molecular weight, such as formic acid, acetic anhydride or acetyl chloride, proprionic anhydride, ethylor methyl-ester of chloro-formic acid, ora cyanate.

The dyestufis, which correspond very probably to the general formula tints. Products which dye yellow and green 7 yellow are obtained by coupling a diazot'izecl aromatic base, such as an aniline, a tolui dine, an anisidine, a cresidine or a chloranihne, and subsequently acylating the dyestuli' obwholeis filtered.

mined; V The-Se llestuifs have in particula v may;

the property that they may be used with advantage for producing grey and green tints,

assuch dyeings arenot'phototropic. Moreover, these dyestuffs are characterized by the very good fastness to light exhibited by their dyeings. For orange dyeings there are used dyestufis of this kind which contain a nitrogroup in the diago component. V

For dyeing-textiles the .dye'stufi'sf which are sparingly soluble or insoluble are preferably used in finely subdivided form, to which endthey areground with a dispersing agent, such as the sulfonated residues obtained in the manufacture of'benzaldehyde or turpentine. oil, 'in the presence of waterto form a fine paste. These pastes can be used for dyeing or they may be converted into preparations capable of beingpowdered cautiously drying them, preferably in a vacuum,- at a temperature not too high "in the presence of further quantities: ofthe nishes, for instance nitrocellulose lacquer,

the new dyestuffs are pure condition.

The following examplesillustrate the invention, the parts being by weight z Example. 1

P efera y used in a ff93parts of aniline are dissolved in 1500 parts of water and250 parts of hydrochloric acid of 30 per cent. strength 500 parts of ice are added'jand the solution is diazotized by mea ns of 70parts 'ofsodium nitrite. ,The

diazo-solution is neutralized with 136 parts of crystallized sodium "acetate and. then therefare introduced 109 parts .ofcmeta-arninophenol. When coupling is .complete the -189 parts of this dyestuffare heated to 100 C. for 41mm with 102partsof acetic anhydride. :The acetic acid is then distilled under reduced pressure. The residue constitutes the new dyestufi' which, if necessary after recrystallization from glacial acetic acid, is a dark yellow powder soluble in organic solvents, such as alcohol or ethylacetate to a yellow solution and capable of dyeing acetate silk very fast greenish-yellow tints which are not phototropic. The formula of the new dyestuff is very probably Ewampl e 2 C HiO 'C -N=NC NHO o-om,

. u 5 and dyes intensely green-yellow tints which are very fast tolight.

Ema/maple 3 4-5 parts of the dyestufi' described in Example 2 are dissolved in 1000 parts of nitrocellulose lacquer. The liquid thus obtained, when spread in thin layers on various supports (metal, glass, leather, wood, celluloid, silk or the like), yields whendry a trans parent coating having an intensely greenyellow, color fast to light. 'By incorporating suitable added materials a transparent lacquer may be converted into a matt lacquer or covering lacquer.

EwampZe 4 I V 10 parts of the dyestufidescribed in EX- ample 2, which have been acetylated by meansof acetic acid anhydride, are stirred with the addition of a suitable dispersing agent, such as Turkey red oil, sulfite cellulose waste liquor or a sulfonation product of the residue of the manufacture of benzaldehyde so as to form a uniform paste containing 20 per cent. of dyestuft. One part of thls paste is very intimately mixed with 10 parts of water of C. and such a quantity of concentrated soap solution that the dyebath to be made from the mixture will cor respond with a soap solution: of 2 per mille strength. The. whole is diluted to make 300 parts; Into the emulsion thus prepared are entered 10 parts of acetate silk yarn. The bath is heated with hour to C. and dyeing is continued for about hour at this temperature. Rinsing and brightening follow. There are obtained, intense, vivid, green-yellow dyeings having very good properties of fastness.

What we claim is 1. A recess for the manufacture of azodyestu s, consisting in coupling diazo-compounds of the benzene series, which contain no substituents capable of bringing about solubility in dilute aqueous caustic alkalies,

with l-amino-3-hydroxybenzene in such media thepH of w ich is not greater than 7, and treating the dyestuffs thus obtained with such acylatlng agents which introduce the residue of an aliphatic carboxylic acid of low molecular weight.

2. A recess for themanufacture of amdyestu s, consisting in coupling diazo-compounds of the general formula in which w'stands for H or O-alkyl, with 1- amino-3-hydroxy-benzene in such media the pH ofwhich is not greater than 7, andtreating the dyestuffs thus obtained with such acylating agents Which introduce the residue of an aliphatic carboxylic acid of low molecular weight. 3. A process for the manufacture of amdyestufls, consisting in coupling diazo-conr pounds of the general formula in which 00 stands for H or Q-alkyl, with l-amino-3-hydroxy-benzene in such media the pH of which is not greater than 7, and treating the dyestufls thus obtained with acetic anhydride. 7 4. Aprocess for the manufacture .of an azo-dyestuff, consisting in coupling l-diazol-methoxy benzene with 1-amino-3-hydroxybenzene in such a medium the pH of which is not greater than 7, and treating the dyestufi thus obtained with acetic anhydride. 5. The dyestuffs of the general formula wherein R means a benzene nucleus which contains no substituents capable of bringing about solubility indilute aqueous caustic alkalies, and R the residue of an aliphatic carboxylic acid of low molecular weight, which products constitute yellow to red powders which dissolve in acetic ester to yellow to orange solutions, and dye acetate silk in aqueous suspensions fast yellow to orange tints.

6. The dyestuffs of the general formula wherein a: means H or O-alkyl, and R the residue of an aliphatic carboxylic acid of low molecular weight, which products constitute yellow powders which dissolve in acetic ester to yellow solutions, and dye acetate silk in aqueous suspensions fast yellow tints.

7 The dyestuffs ofthe general formula wherein a: means H or O-alkyl, which products constitute yellow powders which dis solve in acetic ester to yellow solutions, and dye acetate silk in aqueous suspensions fast yellow tints. i

8. The dyestuif of the formula which product constitutes a yellow powder which dissolves in acetic ester to a yellow solution and dyes acetate silk in an aqueous suspension fast yellow tints.

9. The dyestufl of the formula which product constitutes a yellow powder which dissolves in acetic ester to a yellow solution, and dyes acetate silk in an aqueous 40 suspension fast yellow tints.

In witness whereof we have hereunto signed our names this 21st day of November FRIEDRICH FELIX VVILHELM HUBER. 

